Method and system for hybrid automatic repeat request operation in a semi-persistent scheduling (SPS) interval

Abstract

A method and a base station are provided for transmitting hybrid automatic repeat request (HARQ) packets. The method includes bundling a plurality of HARQ packets in a HARQ process in a semi-persistent scheduling (SPS) grant; and transmitting, to a user equipment (UE), the bundled plurality of HARQ packets in the HARQ process.

What is claimed is: 
     
       1. A method by a base station for transmitting packets, the method comprising:
 bundling a plurality of packets for a HARQ process in a semi-persistent scheduling (SPS) grant period; 
 transmitting, to a user equipment (UE), the bundled plurality of packets for the HARQ process; 
 receiving, from the UE, a response to the transmitted bundled plurality of packets; and 
 retransmitting, to the UE, the bundled plurality of packets in a next SPS grant period, if the response indicates negative acknowledgement. 
 
     
     
       2. The method of  claim 1 , wherein retransmitting the bundled plurality of packets in the next SPS grant period comprises:
 determining whether the SPS grant period is completed; 
 wherein retransmitting the bundled plurality of packets in the next SPS grant period comprises retransmitting the bundled plurality of packets in response to determining that the SPS grant period is completed. 
 
     
     
       3. The method of  claim 2 , wherein retransmitting the bundled plurality of packets in the next SPS grant period further comprises retransmitting the bundled plurality of packets in the SPS grant period, in response to determining that the SPS grant period is not completed. 
     
     
       4. The method of  claim 1 , further comprising:
 allocating a downlink SPS grant period to a group of UEs; and 
 allocating a plurality of packets to the group of UEs within the downlink SPS grant period. 
 
     
     
       5. The method of  claim 4 , wherein the downlink SPS grant period is allocated in an SPS physical downlink control channel (SPS_PDCCH) to the group of UEs. 
     
     
       6. The method of  claim 4 , wherein the plurality of packets is allocated in an SPS physical downlink control channel (SPS_PDCCH) to the group of UEs. 
     
     
       7. The method of  claim 4 , wherein the downlink SPS grant period and the plurality of packets for the downlink SPS grant period include a resource allocation, a modulation and coding scheme (MCS), and link parameters for each UE included in the group of UEs. 
     
     
       8. The method of  claim 7 , wherein the downlink SPS grant period for each included in the group of UEs is different, and
 wherein a summation of the SPS grant periods is less than the SPS grant period allocated to the group of UEs for the MCS and the link parameters for the interval. 
 
     
     
       9. The method of  claim 4 , wherein the group of UEs is allocated with a Cell Radio Network Temporary Identifier (C_RNTI), and
 wherein the C_RNTI is valid until the downlink SPS grant period allocated to the group of UEs is deactivated. 
 
     
     
       10. The method of  claim 9 , wherein the downlink SPS grant period allocation to the group of UEs and the plurality of packets allocation to the group of UEs is deactivated by a Downlink Control Information (DCI) format in an SPS physical downlink control channel (SPS_PDCCH). 
     
     
       11. The method of  claim 1 , further comprising:
 receiving, from the UE, a buffer status indication that indicates an availability of a buffer of the UE to receive downlink packets in a downlink resource allocation; 
 determining if the buffer of the is available to receive the downlink packets; and 
 transmitting the downlink packets in the SPS grant period, in response to determining that the buffer of the UE is available to receive the downlink packets. 
 
     
     
       12. A method by a user equipment (UE) for receiving packets, the method comprising:
 receiving, from a base station, a bundled plurality of packets for a HARQ process in a semi-persistent scheduling (SPS) grant period; 
 transmitting, to the base station, a response to the bundled plurality of packets; 
 receiving, from the base station, the bundled plurality of packets in a next SPS grant period, if the response indicates negative acknowledgement. 
 
     
     
       13. The method of  claim 12 , further comprising:
 generating a buffer status indication that informs the base station to schedule a downlink resource allocation in the SPS grant period; and 
 transmitting the buffer status indication to the base station. 
 
     
     
       14. The method of  claim 13 , wherein the buffer status indication indicates an availability of a buffer of the UE to receive downlink packets in the downlink resource allocation. 
     
     
       15. A chip set configured to:
 bundle a plurality of packets for a HARQ process in a semi-persistent scheduling (SPS) grant period; 
 transmit, to a user equipment (UE), the bundled plurality of packets for the HARQ process; 
 receive a response to the transmitted bundled plurality of packets; and 
 retransmit, to the UE, the bundled plurality of packets in a next SPS grant period, if the response indicates negative acknowledgement. 
 
     
     
       16. The chip set of  claim 15 , wherein the chip set is further configured to retransmit the bundled plurality of packets in the next SPS grant period by:
 determining whether the SPS interval of the SPS grant period is completed; 
 wherein retransmitting the bundled plurality of packets in the next SPS grant period comprises retransmitting the bundled plurality of packets in response to determining that the SPS grant period is completed. 
 
     
     
       17. The chip set of  claim 16 , wherein the chip set is further configured to retransmit the bundled plurality of packets in the next SPS grant period by:
 retransmitting the bundled plurality of packets in the SPS grant period, in response to determining that the SPS grant period is not completed.